Sealing ring with corner lip



Filed Dec. 14, 1961 Q. mi@ m 5 H W. M f 5 0 /mwm m7 @E m F La 46 .J 2

United States Patent O 3,189,359 SEALING RING WITH CRNER UP Robert W.Haberkorn, Minneapolis, Minn., assignor to Minnesota Rubber Company,Minneapolis, Minn., a corporation of Minnesota Filed Dec. 14, 1961, Ser.No. 159,232 14 Claims. (Cl. 277-205) This invention relates to sealingdevices. More particularly, it relates to perfecting a seal between apair of opposed surfaces under unusual circumstances by forming a groovein one of the surfaces and installing a sealing ring of uniquecross-sectional configuration therein.

Under certain conditions it is desirable to perfect a seal between apair of opposed surfaces which can be characterized by low interferenceand a small contact area to insure ease of relative movement of the twosurfaces. An example of this is in automobile brakes. In such usages andin others it is also desirable to provide a maximum wiping action whentraveling in the reverse direction in order to reduce to a minimum thethickness of the iilm which may have been left on the surface againstwhich the seal is perfected. It is also desirable at ltimes to have asealing ring available which will function Isatisfactorily at both highand low pressures. My invention is directed toward providing a solutionto these needs.

It is a general object of my invention to provide a novel and improvedsealing device which is simple and inexpensive to manufacture andutilize.

A more specific object is to provide a novel and improved sealing devicehaving a unique cross-sectional configuration which provides lowinterference and will permit maximum freedom of movement between thesurfaces between which the seal is to be perfected. Another object is toprovide a novel and improved sealing ring which provides a pressureactuated seal yielding an efficient wiping action upon the sealingsurface, low interference, and small contact or sealing area.

Another object is to provide a novel and improved sealing device whichincludes a pressure actuated seal capable of providing an eticient lowinterference, small contact sealing area seal with good wiping action atrelatively low pressure and of also adequately sealing satis. factorilyat high pressures.

These and `other objects and advantages of my invention will more fullyappear from the following description, made in connection with theaccompanying drawings, wherein like reference characters refer to thesame or similar parts throughout the several views, and in which: FIG. 1is a cross-sectional view of a section of the preferred embodiment of myinvention with the approximate proportion indicated thereon.

FIG. 2 is a cross-sectional view of one of my sealing rings designed foruse as an external seal.

' FIG. 3 is a cross-sectional view of another of my sealing rings of thepreferred type designed for use as an internal seal.

FIG. 4 is a cross-sectional view of another of my sealing rings designedfor use as an internal face seal. f FIG. 5 is a vertical sectional viewof a piston and cylinder assembly showing the external seal of FIG. 2mounted therein at the left hand side of the drawing and the internalseal of FIG. 3 mounted therein at the right hand side of the drawing.

FIG. 6 is a fragmentary sectional view showing a pair of surfaces one ofwhich has a sealing groove formed therein and containing the internalface seal of FIG. 4 to perfect a seal between the two surfaces.

The preferred embodiment of my invention shown in FIG. 1 is constructedin the form of a sealing ring which has been indicated generally by thenumeral 10. The ring 3,139,359 Patented ...lune 15, 1965 ICC 10 ispreferably made of a resilient flowable material such as rubberthroughout and is adapted to be fitted into a sealing groove ofring-like configuration as illustrated in FIGS. 5 and 6. It will benoted by reference to FIG. 1 that the sealing ring in its free form isgenerally square in cross-sectional configuration and that each of itsfour sides are concavely shaped. Three of the sides indicated in FIGS. 1and 2 a-s 11, 12, and 13 are of relatively shallow concavity and havethe same radius. The fourth side 14, however, has a relatively largeconcavity 15 which extends inwardly the major portion of the distancetoward the cross-sectional center which has been indicated in FIG. 1 bythe numeral 16. This deep concavity 15 in cooperation with the adjacentside 11 defines an annular sealing lip indicated generally by thenumeral 17.

As shown the sealing lip 17 has a. iiat end 1S and an acutely angledsealing contact 19 which is defined by the flat end sur/face 18 and theadjacent side 11. This contact 19 provides a minimum contact area andwhen followed around the ring provides a contact line indicated by thenumeral 20 in FIGS. 3 `and 4. The acutely angled contact portion 19 ofthe sealing lip 17 is in sharp contrast to the convexly shaped lobes 21,22, and 23 at each of the other three corners of the sealing ring whenconsidered cross-scctionally.

It will be noted by reference lto the drawings that the flat end surface18 of the sealing lip 17 of my sealing ring terminates Vshort of thelobe at the opposite side of the large concavity 15, this particularlobe having been identiiied by the numeral 23. It will also be notedthat the Contact 19 of the sealing lip 17 extends outwardly beyond thelobe 21 of the adjacent side 11 to provide a cantilever projectionmounting for the contact 19.

FIG. 2 illustrates a sealing ring of my unique crosssectionalconfiguration designed to perfect an external seal as illustrated inFIG. 5. It will be noted that in FIG. 5 there is shown a cylinder 24having an internal surface 25 and a piston 26 having an external surface27. The external seal mounted on the piston in the groove 28 providedfor that purpose perfects the seal between .the surfaces 25 and 27. Itwill be noted that the Contact -19 at the apex of the acutely shapedangle of the sealing lip 17 bears against the surface 25 and perfectsthe seal between the piston 26 and the cylinder 24. The direction ofpressure has been indicated by the arrow identified by the numeral 29.It will be noted that the side wall 14 in which the large or deepconcavity 15 is formed faces in the direction from which the pressure isapplied as indicated by the arrow 29. It will also be noted that thesealing lip 17 extends outwardly from the cross-sectional center 16 inav direction toward that from which the pressure is applied.

FIG. 3 shows one of my seals designed particularly 'for use as aninternal seal such as is illustrated at the right hand side of FIG. 5.In that figure a groove 30 is formed in the portion of the cylinderthrough which the piston rod 31 passes. The bore surface 32 is disposedopposite to the exterior surface 33 of the piston rod and the groovefaces toward the piston rod. Within the groove 30 is one of my sealingrings with the sealing lip 17 having itscontacts 19 bearing against theexternal. surface 33 of the piston rod and perfecting a seal between.the rod and the cylinder. Again it will be noted that the side in whichthe large concavity is formed faces in the direction in which thepressure is applied and the sealing lip 17 extends outwardly relative tothe cross-sectional center of the ring in the direction from which thepressure is applied. It will also be noted that the flat end 1S of thesealing lip 17 extends in .a radial direction relative to the ring as isthe case with the external seal shown in FIG. 2.

FIG. 4 shows one of my sealing rings of the type designed to perfect aninternal seal in what is commonly referred to as a face seal. FIG. 6shows a body 34 having a surface 35 opposed to a body 36 having anopposed surface 37 in which a groove 38 is formed. The groove 3S extendsaround a central opening 39 through which pressure is applied in thedirection of the -arrow shown and identified by the numeral 44B. It willbe noted in this instance that the flat end of the sealing lip extendsin an axial direction relative to the sealing ring 10 but other thanthat its construction is highly similar to that of the ring shown inFIGS. 2 and 3. In each of these constructions the sealing ring ischaracterized by a generally square cross-sectional configuration threecorners of which have convexly shaped lobes and the fourth corner ofwhich utilizes a cantilever projection as a sealing lip to provide Ianimproved function. In this connection it will be noted that at lowpressure the cantilever projection provides ample pressure between thecontact 19 and the surface against which it is to bear to perfect thedesired seal. Since the contact 19 is disposed outwardly of the cornerlobe of the adjacent side which defines the Contact, this means that thelip 17 must be bent inwardly toward the large cavity 15 in assemblingthe same within the groove, such as the groove 28, or 30. In eachinstance the con tact 19 is urged against the opposite surface by theinherent resiliency of the material from which the sealing ring is madeto perfect the seal and the pressure supplied thereby is ample tomaintain `the desired seal. It will be noted that on the return stroke,which is to the left as viewed in FIG. ,5, the lip 17 is moved forwardlyto the left and `the sharply angled contact 19 will wipe the surfaceclean to effectively reduce the thickness of the film of fluid which hasremained on the cylinder wall. I have found that this type of sealinglip does a more efficient wiping job than the conventional convexlyshaped seal which has heretofore been utilized. It should also be notedthat the application of pressure is such that the pressure has readyaccess to the large cavity 15 which tends to urge the lip 17 outwardlyand thus provide a pressure actuated seal. By the same token, when highpressure is applied to my sealing ring when installed as shown, theconvexly shaped lobe 21 as viewed in FIG. will function to provide ahighly satisfactory seal even at such pressures. Thus a seal of thisdesign in addition to being an effective seal at low pressure may alsobe utilized at high pressure so that the seal is adaptable to a widerrange of circumstances.

It will be noted that since the contact 19 is supported by a cantileverprojection, there is low interference and hence low friction between thesealing lip 17 and the surface Z5 against which it bears. This insuresease of movement of the piston 2.6 and since such a function is highlydesirable in instances such as automobile brakes, the seal is valuablefor such usage.

It will also be noted that the sharply angled contact portion 19 of thesealing lip 17 engages only a very small contact area upon the surface25 because of its configuration. This also reduces friction and assuresease of movement of the piston relative to the cylinder wall. Y Anadditional advantage of my sealing ring is that because of thecantilever projection of the sealing lip 17, this sealing ringautomatically compensates for wider tolerances in the construction ofthe groove and the spacing between the surfaces between which the sealis to be perfected. This also makes the ring more desirable in that itsadaptability and usability is increased.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the parts withoutdeparting from the scope of my invention which consists of the mattershown and described herein and set forth in the appended claims.

What is claimed is:

1. A fluid seal comprising,

(a) a pair of contiguous surfaces, one of said surfaces having anannular sealing groove formed therein opposite to and facing the otherof said surfaces and adapted to receive a Sealing ring therein,

(b) fiuid under pressure disposed between said surfaces with thepressure appied in a predetermined direction across said groove,

(c) and a pressure actuated sealing ring disposed within said groove andeffecting a seal between said surfaces,

(d) said sealing ring being comprised of a continuously formed ring-likemember made of a resilient fiowable material such as rubber throughoutand adapted to be fitted into said sealing groove,

(e) said sealing ring in its free form having a substantiallyrectangular cross-sectional configuration throughout its continuousextent and having a convexly shaped lobe at three of its corners betweenadjacent sides (f) said sealing ring when considered cross-sectionallyhaving a concavity formed in each of its sides, one of said concavitiesbeing substantially deeper than the others and defining with an adjacentside an an- `annular sealing lip extending away from the remaining twosides of said member,

(g) two of said convexly shaped corner lobes of said ring being disposedin the bottom of said groove and said sealing lip extending outwardlyfrom the groove and bearing against the surface disposed opposite saidgroove to effect a seal between -said surfaces.

2. The structure defined in claim 1 wherein said sealing lip extendsoutwardly from the cross-sectional center of said ring toward thedirection from which the pressure is applied.

3. The structure defined in claim 1 wherein said deep concavity formedin said sealing ring is formed in the side facing the direction fromwhich the pressure is applied to said uid.

4. The structure defined in claim 1 wherein said sealing lip in its freeform extends outwardly beyond the lobed corner of said adjacent side.

5. The structure defined in claim 1 wherein each of the four sides ofsaid sealing ring are concavely shaped and the concavity facing thedirection from which the pressure is applied is substantially deeperthan the others.

6. The structure defined in claim 1 wherein said sealing lip terminatesat a point a greater distance away from the cross-sectional center ofsaid member than anyy of its lobed corners and terminates in a fiat endsurface which in cooperation with said adjacent side of said ringdefines an acutely angled sealing contact which bears against the saidsurface disposed opposite said groove.

7. A sealing device comprising:

(a) a continuously formed ring-like member made of a resilient flowablematerial such as rubber throughout and adapted to be fittedr into asealing groove of ring-like configuration,

(b) said ring-like member in its free form having a substantial-lyrectangular cross-sectional configuration throughout its continuousextent with four concave sides and a lobe at three of its cornersbetween adjacent sides,

(c) the exterior surface of said lobes being convex in shape,

(d) the concavity of one of the sides of said member being substantiallygreater than at any of the other of its sides and defining with theconcavity of an adjacent side an annular sealing lip extending away fromthe remaining two `sides of said members,

(e) the greatest dimension of said lip being less than the largestcross-sectional dimension of the remainder of said rectangular member.

8. The structure defined in claim 7 wherein said lip terminates at apoint a greater distance away from the cross-sectional center of saidmember than any one of its lobed corners.

9. The structure defined in claim 7 wherein said lip terminates at apoint a greater distance away from the cross-sectional center of saidmember than either of its adjacent lobed corners.

10. The structure deined in claim 7 wherein said lip when consideredcross-sectionally has an acutely angled sealing apex which defines acircumferentially extending sealing contact line for said member.

11. The structure dened in claim 7 wherein said lip has a flat endsurface extending radially of said member.

12. The structure defined in claim 7 wherein said lip extends outwardlybeyond the lobed corner of said adjacent side.

13. The structure defined in claim 7 wherein said sealing lip terminatesin a at end surface extending generally parallel to the axis of saidmember.

14. The structure dened in claim 7 wherein said sealing lip terminatesin a iiat end surface which in cooperation with said adjacent side ofsaid member deiines an acutely angled sealing contact.

References Cited bythe Examiner UNITED STATES PATENTS LEWIS I. LENNY,Primary Examiner.

WALTER A. SCHEEL, EDWARD V. BENHAM.

Examiners.

1. A FLUID SEAL COMPRISING, (A) A PAIR OF CONTIGUOUS SURFACES, ONE OFSAID SURFACES HAVING AN ANNULAR SEALING GROOVE FORMED THEREIN OPPOSITETO AND FACING THE OTHER OF SAID SURFACES AND ADAPTED TO RECEIVE ASEALING RING THEREIN, (B) FLUID UNDER PRESSURE DISPOSED BETWEEN SAIDSURFACES WITH THE PRESSURE APPLIED IN A PREDETERMINED DIRECTION ACROSSSAID GROOVE, (C) AND A PRESSURE ACTUATED SEALING RING DISPOSED WITHINSAID GROOVE AND EFFECTING A SEAL BETWEEN SAID SURFACES, (D) SAID SEALINGRING BEING COMPRISED OF A CONTINUOUSLY FORMED RING-LIKE MEMBER MADE OF ARESILIENT FLOWABLE MATERIAL SUCH AS RUBBER THROUGHOUT AND ADAPTED ABLEMATERIAL INTO SAID SEALING GROOVE, (E) SAID SEALING RING IN ITS FREEFORM HAVING A SUBSTANTIALLY RECTANGULAR CROSS-SECTIONAL CONFIGURATIONTHROUGHOUT ITS CONTINUOUS EXTENT AND HAVING A CON-